|Yuswan Muharam||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Jessica Adeline Soedarsono||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
The hydrodeoxygenation of vegetable oil in a trickle bed reactor for renewable diesel production was observed in this research. Vegetable oil was represented by triolein. The NiMo/Al2O3 catalyst with a composition of 6.13% w/w Ni, 12.49% w/w Mo, and 81.33% w/w Al2O3 was used. The reactions took place in the temperature range of 272-327.5°C and pressures of 5 and 15 bar. A trickle bed reactor of 2.01 cm in diameter and 24 cm in bed length was able to convert triolein into renewable diesel. C18 hydrocarbons became the dominant reacting compounds at temperatures above 310°C and a pressure of 15 bar, which reached more than 50% w/w. At 5 bar pressure, fatty acids with stearic acid as the acid with the highest concentration were the dominant reacting component, reaching more than 60% w/w at temperatures above 280°C. This led to double bond saturation once the reactants were mixed.
Hydrodeoxygenation; Renewable diesel; Trickle bed reactor
The Fuel is one of the basic needs for transportation and industry, which mostly comes from petroleum processing (fossil-based). Economic oil reserves are depleting, while energy demand continues to increase with population size and advancing technology. Moreover, fossil fuel produces a high content of carbon dioxide in its combustion (Pinzi and Dorado, 2012). Currently, the world consumes around 13 TW of energy each year, and 80% of it is obtained from fossil fuels. Seeing the energy demand and opportunity of the chemical industry’s rapid growth in converting hydrocarbon into chemical products, it was projected that in the future, the energy sector will be dominated by renewable fuel. In 2030, renewable fuel is targeted to increase four times compared to that in 2010 (Douvartzides et al., 2019).
renewable fuel is more environmentally friendly in terms of emissions.
Currently, renewable diesel is one of the most rapidly developed renewable
resources since its characteristics are similar to petrodiesel, and its cetane
number is high. It consists of straight-chain alkanes in the range of diesel
fuel (C15-C18). In addition to its advantages, the cost
to produce renewable diesel is becoming more competitive with that of fossil
fuels. This shows that shifting from fossil
fuel domination to renewable energy will indirectly have a positive
economic impact (Setiawan and Asvial, 2016).
Renewable diesel is produced from vegetable oil. Triglycerides are the main component of vegetable oil, but its high viscosity and instability requires it to be treated before use. Among all processes, hydrotreating is the most advanced method from the point of view of technology and research due to its product characteristics and ability to utilize existing systems in oil refinery (Holmgren, 2007).
In hydrotreating, vegetable oil as a feed reacts with hydrogen gas. Hydrogen binds with oxygen in the triglyceride; therefore, it is called hydrodeoxygenation and produces alkanes with the same carbon number as its feed. Catalysts with active sites of nickel and molybdenum are frequently used (Kubi?ka et al., 2010; Bezergianni and Dimitriadis, 2013). However, most research favors using molybdenum as an active site, such as that by Gong et al. (2012). They carried out hydrodeoxygenation using vegetable oil with a NiMoP/Al2O3 catalyst and molybdenum as an active site, producing long chain alkanes with a renewable diesel range. Attanatho (2012) had a 99.7% conversion and 26.25% hydrodeoxygenation.
Understanding the importance of effective production of renewable diesel, research and development needs to be performed further. In this research, triolein was used as a model compound. Triolein with oleic acid as its fatty acid compound experiences hydrogenolysis to become fatty acid and fatty alcohol. Both are intermediate to produce long-chain alkanes with a selective deoxygenation process. Triolein was chosen because of its fatty acid composition, C18:1, which is the fatty acid of the highest composition in most vegetable oils. Moreover, using a model compound allows a thorough understanding of reaction pathways.
Hydrodeoxygenation of vegetable oil represented by triolein for renewable diesel production was investigated in a trickle bed reactor of 2.01 cm in diameter and 24 cm in bed length. C18 hydrocarbons became dominant reacting compounds at temperatures above 310°C and a pressure of 15 bar, which reached more than 50% w/w. At 5 bar pressure, fatty acids with stearic acid as the acid with the highest concentration were the dominant reacting component, reaching more than 60% w/w at temperatures above 280°C. This led to double bond saturation once the reactants mixed.
We express our gratitude to Universitas Indonesia, which funded this research through the scheme of Publikasi Terindeks Internasional (PUTI) Prosiding Tahun Anggaran 2020 Nr NKB-1194/UN2.RST/HKP.05.00/2020.
Attanatho, L., 2012. Performances and Kinetic Studies of Hydrotreating of Bio-Oils in Microreactor. Master’s Thesis, Graduate Program, Oregon State University, Corvallis, United States of America
Ayodele, O.B., Abbas, H.F., Daud, W.M.A.W., 2014. Catalytic Upgrading of Oleic Acid into Biofuel using Mo Modified Zeolite Supported Ni Oxalate Catalyst Functionalized with Fluoride Ion. Energy Conversion and Management, Volume 88, pp. 1111–1119
Bezergianni, S., Dimitriadis, A., 2013. Catalytic Hydrotreating of Waste Cooking Oil for Renewable Diesel Production. In: Proceedings of the 9th International Colloquium on Fuels Conventional and Future Energy for Automobiles, Ostfildern, Germany
Douvartzides, S.L., Charisiou, N.D., Goula, M.A., Papageridis, K.N., 2019. Green Diesel: Biomass Feedstocks, Production Technologies, Catalytic Research, Fuel Properties and Performance in Compression Ignition Internal Combustion Engines. Energies, Volume 12(5), pp. 1–4
Gong, S., Shinozaki, A., Shi, M., Qian, E.W., 2012. Hydrotreating of Jatropha Oil over Alumina Based Catalysts. Energy and Fuels, Volume 26(4), pp. 2394–2399
Heriyanto, H., Murti, S., Heriyanti, S.I., Sholehah, I., Rahmawati, A., 2018. Synthesis of Green Diesel from Waste Cooking Oil through Hydrodeoxygenation Technology with NiMo/?-Al2O3 Catalysts. MATEC Web of Conferences , Volume 156, pp. 1–6
Holmgren, J., 2007. Green Diesel Production from Vegetable Oil. In: 2007 Spring AIChE Conference, Houston, United States of America
Kubi?ka, D.., Vik, J., Bejblová, M., 2010. Conversion of Vegetable Oils into Hydrocarbons over CoMo/MCM-41 Catalysts. Topics in Catalysis, Volume 53, pp. 168–178
Mortensen, P.M., Gardini, D., Carvalho, W.P.D., Damsgaard, C.D., Grunwaldt, J., Jensen, P.A., Wagner, J.B., Jensen, A.D., 2014. Stability and Resistance of Nickel Catalysts for Hydrodeoxygenation: Carbon Deposition and Effects of Sulfur, Potassium, and Chlorine in the Feed. Catalysis Science & Technology, Volume 4, pp. 3672–3686
Muharam, Y., Nugraha, O.A., 2017. Prediction of the Effects of the Inlet Velocity and the Reactor Length on the Performance of a Trickle-Bed Reactor for Renewable Diesel Production. Journal of Computational and Theoretical Nanoscience, Volume 23(6), pp. 5609–5614
Muharam, Y., Putri, A.D., 2018. Simulation of Hydrotreating of Vegetable Oil in a Slurry Bubble Column Reactor for Green Diesel Production. International Journal of Technology, Volume 9(6), pp. 1168–1177
Pinzi, S., Dorado, M.P., 2012. Feedstocks for Advanced Biodiesel Production. In: Advances in Biodiesel Production, Woodhead Publishing, York, North Yorkshire, United Kingdom, pp. 69–90
Setiawan, E.A., Asvial, M., 2016. Renewable Energy’s Role in a Changing World. International Journal of Technology, Volume 7(8), pp. 2087–2100
Susanto, B.H., Prakasa, M.B., Nasikin, M., Sukirno, S., 2016. Synthesis of Renewable Diesel from Palm Oil and Jatropha Curcas Oil through Hydrodeoxygenation using NiMo/Zal. International Journal of Technology, Volume 7(8), pp. 1405–1412
Tóth, C., Baladincz, P., Kovács, S., Hancsók. J., 2011. Producing Clean Diesel Fuel by Co-hydrogenation of Vegetable Oil with Gas Oil. Clean Technologies and Environmental Policy, Volume 13, pp. 581–585
Veriansyah, B., Han, J.Y., Kim, S.K., Hong, S.A., Kim, Y.J., Lim, J.S., Shu, Y.W., Oh, S.G., Kim, J., 2012. Production of Renewable Diesel by Hydroprocessing of Soybean Oil: Effect of Catalysts. Fuel, Volume 94, pp. 578–585
Wu, C., Tu, X., 2016. Biological and Fermentative Conversion of Syngas. In: Handbook of Biofuels Production, pp. 335–357. Edited by Rafael Luque, Carol Sze Ki Lin, Karen Wilson and James Clark